DE102005049982A1 - Device for conveying fuel - Google Patents

Abstract

Known devices have a valve housing in which a pressure relief valve and a check valve are arranged parallel to one another, the pressure relief valve having a first inlet which opens downstream of a valve seat into a valve chamber in which a valve body is arranged movably and which is connected via a first outlet to a second one The inlet for the check valve is connected to the flow. It is disadvantageous that the first outlet is arranged in the valve chamber such that there is an axial outflow from the valve chamber of the pressure relief valve. As a result of the axial outflow, only a comparatively small impulse force is exerted on the valve body, which therefore executes only a comparatively small opening stroke at a given volume flow. The control behavior is therefore not optimal. DOLLAR A In the device according to the invention, the control behavior of the pressure relief valve is improved. DOLLAR A According to the invention, the first outlet (26.1) is provided on the circumference of the valve chamber (36) and is arranged in the axial direction with respect to a valve axis (38) such that an essentially radial outflow from the valve chamber (36) occurs when the pressure relief valve (23) is open. in the second input (25.2).

Description

The The invention is based on a device for conveying fuel after the Genus of the main claim.

There is already a device for pumping fuel out of the DE 195 27 0134 A1 known, with a valve housing, in which a pressure relief valve and a check valve are arranged parallel to each other, wherein the pressure relief valve has a first input, which opens downstream of a valve seat in a valve chamber in which a valve body arranged to be movable and via a first output to a second Inlet for the check valve is fluidly connected. The disadvantage is that the first output is arranged in the valve chamber, that results in an axial outflow from the valve chamber of the pressure relief valve out. Due to the axial outflow, only a comparatively small impulse force is exerted on the valve body, which thereby performs only a comparatively small opening stroke for a given volume flow. The control behavior is therefore not optimal.

Advantages of invention

The inventive device to promote of fuel with the characterizing features of the main claim has in contrast the advantage that on simple way the control behavior of the pressure relief valve is improved by the first outlet at the periphery of the valve chamber provided and arranged in the axial direction such that when open Pressure relief valve a substantially radial outflow the valve chamber out into the second input results.

By in the subclaims listed activities are advantageous developments and improvements in the main claim specified device possible.

Especially advantageous when the pressure relief valve and the check valve in the axial direction are arranged offset from one another such that the first outlet of the pressure relief valve in the radial direction in the second input of the check valve empties. In this way, a radial outflow into the second input the check valve reached.

Farther is advantageous if the valve housing a first recess for Insertion of the pressure relief valve and a second input for the check valve has forming second recess, as this embodiment is particularly economical can be produced. The first recess and the second recess are by means of a Wall separated from each other.

Very It is advantageous if the valve housing two cylinder sections has, in each of which one of the recesses are provided, there this execution very space is saving.

Also is advantageous if the pressure relief valve has a separate housing, on which the valve seat is formed and in which the valve chamber with the valve body is provided because in this way the valve housing is simplified and cheaper can be produced.

Furthermore is advantageous if the housing the pressure relief valve arranged directly on the delivery unit and is firmly connected to this.

drawing

An embodiment of the invention is shown in simplified form in the drawing and explained in more detail in the following description. Show it 1 schematically a device for conveying fuel, 2 a simplified sectional view of a valve housing according to the invention with a check valve and a parallel pressure relief valve and 3 a plan view of the valve housing.

description of the embodiment

1 shows schematically a device for conveying fuel.

The Device serves for example for conveying fuel. But it can expressly too other liquids promoted by the device become.

The device has a delivery unit 1 on, the fuel at least indirectly from a reservoir 2 sucks and pressure increases via a pressure line 3 to an internal combustion engine 4 For example, in a fuel rail 5 , promotes. The fuel distributor 5 is with injectors 6 fluidly connected, the fuel in each case in a combustion chamber, not shown, of the internal combustion engine 4 inject.

The delivery unit 1 is for example in the reservoir 2 arranged and there, for example, within a storage container 9 intended. The delivery unit 1 sucks fuel out of the sem storage tank 9 on, for example via a pre-filter 10 , and promotes this via the pressure line 3 to the internal combustion engine 4 , The pre-filter 10 protects the device downstream of the prefilter 10 in front of coarse dirt particles contained in the fuel. In the pressure line 3 is for example a check valve 11 provided so no fuel from downstream of the check valve 11 after upstream of the check valve 11 flows back. In addition, in the pressure line 3 downstream of the check valve 11 for example, a main filter 12 provided that filters out fine dirt particles from the fuel. Downstream of the delivery unit 1 and upstream of the check valve 11 branches a leash line 13 from the pressure line 3 and at least indirectly leads back into the storage container 9 , The volume flow of the treble line 13 drives, for example, a so-called suction jet pump 16 on, the fuel from the reservoir 2 in the storage tank 9 promotes. The example cup-shaped storage container 9 stores enough fuel, so even when cornering and the consequent sloshing movements of the fuel in the reservoir 2 a fuel supply of the internal combustion engine 4 through the delivery unit 1 is ensured.

The suction jet pump 16 is to be interpreted that the storage container 9 regardless of the level in the reservoir 2 remains filled and does not run empty. The suction jet pump 20 As is known, has a throttle element, for example, a nozzle 17 about which the fuel of the haulage line 13 in one with the reservoir 2 flow-connected suction chamber 18 arrives. The one out of the nozzle 17 in the suction room 18 escaping jet breaks fuel out of the suction chamber 18 with, so that in a known manner the fuel of the propulsion jet and the entrained Kraftsoff via a mixing channel 19 in the storage tank 9 reach.

Downstream of the check valve 11 and, for example, downstream of the main filter 12 branches a return line 22 from the pressure line 3 off, back to the pressure line 3 upstream of the check valve 11 leads and a pressure relief valve 23 having.

According to the invention, the check valve 11 and the pressure relief valve 23 on a common valve housing 24 educated.

2 shows a valve housing according to the invention with a check valve and a pressure relief valve arranged in parallel.

In the device according to 2 are the opposite to the device according to 1 Constant or equivalent parts by the same reference numerals.

The valve housing 24 has a first entrance 25.1 and a first exit 26.1 for the pressure relief valve 23 as well as a second entrance 25.2 and a second exit 26.2 for the check valve 11 , The first exit 26.1 the pressure relief valve 23 flows directly into the second entrance 25.2 the check valve 11 ,

The valve housing 24 has two separate, for example cup-shaped depressions 27.1 . 27.2 on, passing through a wall 29 are separated from each other. In a first recess 27.1 is the pressure relief valve 23 arranged and a second recess 27.2 forms the second entrance 25.2 for the check valve 11 , The valve housing 24 is with the second recess 27.2 on an outlet nozzle 28 of the delivery unit 1 pluggable, reducing the flow connection between the outlet nozzle 28 of the delivery unit 1 and the valve housing 24 tightly closed. The valve housing 24 is in this way directly on the delivery unit 1 arranged. The valve housing 24 is by means of a valve housing 24 arranged bracket 34 positive and / or non-positive and / or cohesive with the delivery unit 1 connected. For example, the holder is positively and / or force-locking to an electrical plug 41 of the delivery unit 1 attached.

The wells 27.1 . 27.2 are for example on two cylindrical housing sections of the valve housing 24 provided, wherein at a first cylinder portion 24.1 the first depression 27.1 and at a second cylinder portion 24.2 the second recess 27.2 is trained. The two cylinder sections 24.1 . 24.2 of the valve housing 24 are integrally connected. The first cylinder section 24.1 surmounted the second cylinder section 24.2 in its longitudinal extension. The first entrance 25.1 is at an end face of the first cylinder portion 24.1 and the second entrance 25.2 at one of the first entrance 25.1 remote end face of the second cylinder portion 24.2 arranged.

The first recess 27.1 is by means of a lid 33 closed, with a paragraph 34 for example, in the first well 27.1 protrudes. In this way, the pressure relief valve 23 in the first recess 27.1 sealed against the atmosphere.

At one of the second entrance 25.2 remote end face of the second cylinder portion 24.2 is a neck 30 arranged in which the check valve 11 is provided. The second entrance 25.2 flows through a connecting channel 31 in one in the neck 30 trained further valve chamber 45 the check valve 11 , In the further valve came mer 45 is another valve body 46 movably mounted, with another valve seat 47 interacts.

That in the first well 27.1 arranged pressure relief valve 23 has one with a valve seat 35 cooperating valve body 36 up in a valve chamber 37 in the axial direction with respect to a valve axis 38 is movably mounted. The valve body 36 is by means of a valve spring 39 in the direction of the valve seat 35 pressed. The valve seat 35 is designed for example as a flat seat and acts with a flat end face of the example cylindrical valve body 36 together. The valve seat 35 is on a front wall 40 the valve chamber 37 for example, formed annularly increased.

The pressure relief valve 23 For example, has its own, separate housing 42 at which the valve seat 35 is formed and in which the valve chamber 37 with the valve body 36 and with the valve spring 39 are provided.

According to the invention, the first output 25.1 the pressure relief valve 23 at the periphery of the valve chamber 37 provided and in the axial direction with respect to the valve axis 38 arranged such that when the pressure relief valve is open 23 a substantially radial outflow from the valve chamber 37 in the first exit 25.1 and in the second entrance 25.2 results. The first exit 25.1 the pressure relief valve 23 is in the axial direction with respect to the valve axis 38 near the valve seat 35 , For example, in the same axial position, arranged. The first exit 25.1 for example, passes through a first opening 20 on the circumference of the housing 32 the pressure relief valve 23 and through a second opening 21 in the wall 29 between the wells 27.1 . 27.2 , The first opening 20 and the second opening 21 are arranged in alignment with each other. The pressure relief valve 23 and the check valve 11 are in the axial direction with respect to the valve axis 38 arranged offset to one another such that the first output 25.1 the pressure relief valve 23 in the radial direction with respect to the valve axis 38 in the second entrance 25.2 empties.

Exceeds the pressure in the return line 22 one of the spring force of the valve spring 39 dependent predetermined value, so raises the valve body 36 from the valve seat 35 and opens in this way the pressure relief valve 23 , After opening the pressure relief valve 23 fuel flows over the axial first input 25.1 and one between the valve seat 35 and the valve body 36 formed gap in the axial direction in the valve chamber 37 and leaves them in the radial direction over the first exit 26.1 , Due to the flat seat, the flow can flow off particularly well radially.

On the valve body 36 acts by the deflection of the fluid from axial to radial direction occurring impulse force, this in from the valve seat 35 opposite direction against the spring force of the valve spring 39 moves until an equilibrium of forces with the spring force is reached. The momentum of the flow increases with increasing flow through the pressure relief valve 23 at. The spring force of the valve spring 39 decreases as the stroke of the valve body increases 36 linear to. With axial inflow through the first entrance 25.1 in the valve chamber 37 and in accordance with the invention radial outflow from the valve chamber 37 is that of the fuel on the valve body 36 applied momentum greatest. In the prior art with axial inflow and outflow, however, results in a smaller on the valve body 36 acting momentum.

The Impuskraft counteracts the spring force. Ideally, the increasing impulse force with increasing flow compensates for the stroke movement of the valve body 36 increasing spring force. Thus, the control pressure is kept largely independent of the flow.

The larger the on the valve body 36 acting momentum force, the greater is that of the valve body 36 executed opening stroke and the lower the total pressure loss of the pressure relief valve 23 for a given flow.

The total pressure loss of the pressure relief valve 23 essentially results from the pressure loss in the gap between the valve seat 35 and the valve body 36 , The pressure loss at this gap decreases with increasing stroke of the valve body 36 ,

In the prior art with axial outflow, however, falls an additional pressure loss in the axial flow around the valve body 36 at. This additional pressure loss in the prior art increases with increasing flow. The additional pressure loss in the prior art falls in the pressure relief valve according to the invention 23 not on, since no axial flow around the valve body 36 but a radial outflow takes place.

The elimination of the additional pressure loss results in a comparison with the prior art better control behavior of the pressure relief valve 23 because the overall pressure loss changes less with small flow changes. In this way, the pressure in the return line 22 and in the pressure line 3 kept almost constant.

3 shows a plan view of the valve housing according to the invention.

In the device according to 3 are the ge towards the device 1 and 2 Constant or equivalent parts by the same reference numerals.

Claims (10)

Device for conveying fuel with a valve housing, in which a pressure relief valve and a check valve are arranged parallel to each other, wherein the pressure relief valve has a first input, which opens downstream of a valve seat in a valve chamber in which a valve body arranged movably and which via a first output is fluidly connected to a second input for the check valve, characterized in that the first output ( 26.1 ) at the periphery of the valve chamber ( 36 ) and in the axial direction with respect to a valve axis ( 38 ) is arranged such that when the pressure relief valve ( 23 ) a substantially radial outflow from the valve chamber ( 36 ) in the second input ( 25.2 ). Apparatus according to claim 1, characterized in that the pressure relief valve ( 23 ) and the check valve ( 11 ) are arranged offset in the axial direction such that the first output ( 26.1 ) of the pressure relief valve ( 23 ) in the radial direction in the second input ( 25.2 ) of the check valve ( 11 ) opens. Device according to claim 1, characterized in that the valve housing ( 24 ) a first recess ( 27.1 ) for inserting the pressure relief valve ( 23 ) and a second input ( 25.2 ) for the check valve ( 11 ) forming second depression ( 27.2 ) having. Apparatus according to claim 3, characterized in that the first recess ( 27.1 ) and the second recess ( 27.2 ) by means of a wall ( 29 ) are separated from each other. Device according to claim 3, characterized in that the depressions ( 27.1 . 27.2 ) on cylindrical housing sections ( 24.1 . 24.2 ) are provided. Apparatus according to claim 3, characterized in that the first recess ( 27.1 ) by means of a lid ( 33 ) is closed. Device according to claim 5 , characterized in that the cylindrical housing sections ( 24.1 . 24.2 ) are integrally connected. Apparatus according to claim 1, characterized in that the pressure relief valve ( 23 ) a separate housing ( 32 ), on which the valve seat ( 35 ) and in which the valve chamber ( 37 ) with the valve body ( 36 ) is provided. Device according to claim 1, characterized in that the valve seat ( 35 ) is designed as a flat seat. Device according to claim 1, characterized in that the valve body ( 36 ) by means of a valve spring ( 39 ) in the direction of the valve seat ( 35 ) is pressed.